A number of electronic high frequency switching AC voltage controllers have been devised for delivering a variable sinusoidal output voltage. U.S. Pat. No. 5,018,058 discloses how to obtain a pure sinusoidal output voltage waveform from the AC line voltage using switchmode electronic circuitry. Furthermore, U.S. Pat. Nos. 5,500,575 and 5,714,847 show other methods of obtaining a variable AC output voltage having a sinusoidal waveform. Although existing electronic high frequency switchmode AC voltage controller have several major advantages, such as a small size and weight and a relatively low manufacturing cost, their main disadvantage is the lack of capacity to correct the output voltage waveform when a heavy inductive and non-linear load, such as an electromagnetic ballast and a HID lamp are present. The result is a relatively large distortion of the output voltage that decreases the overall system efficiency.